1. Field of the Invention
The present invention relates to an apparatus and method for scarifying a railway tie bed, thereby providing sufficient space within the ballast for insertion of a replacement railway tie. More specifically, the present invention includes a scarifier capable of being mounted on a tie insertion/removal vehicle.
2. Description of the Related Art
Scarifying is a step in the process of removing and replacing old railway ties, wherein some of the ballast immediately surrounding the space formerly occupied by the old tie is removed, thereby providing additional space for insertion of the new tie. Although the present trend is to minimize the frequency with which this step is performed, scarifying is still helpful in locations wherein the ballast has been compacted and/or contaminated, resulting in excessive difficulty in inserting the new tie.
One proposed system of displacing ballast includes a pointed plow having a plurality of lateral ejectors, with each ejector reciprocating between a first position wherein one end of the ejector protrudes from the plow, and the opposite end is retracted, and a second position wherein the previously retracted end of the ejector is now extended, and the first end of the ejector is retracted within the plow. The lateral ejectors may be actuated in pairs, so that when one ejector is moved towards one side of the plow, a corresponding ejector is moved towards the opposite side of the plow.
Another proposed scarifying device includes horizontally and vertically reciprocating ballast clearing elements. The ballast clearing elements are moved vertically by a vertical displacement drive and vertical displacement guides. The ballast clearing elements and associated carrier are moved horizontally as a unit. The ballast clearing elements are pivotally secured to the carrier at their top ends, permitting them to pivot upward and outward.
Yet another proposed scarifying device includes a rotating drum having a plurality of pivotally attached hammer arms. Each hammer arm includes tool at its end for removing ballast, and a tie protecting portion on its front surface. As the drum rotates, the hammer arms are pulled outward by centrifugal force, causing the tooth of the hammer to strike the ballast, thereby removing the ballast from the desired location. When the rotating drum passes over a tie, the tie protecting portion of the hammer will strike the tie before the tooth, causing the hammer to be deflected towards the drum, preventing the tooth from damaging the tie.
Lastly, another scarifying apparatus includes three digging plates, with one digging plate extending between the tracks, and the other two digging plates each located on one side of the tracks.
The majority of the presently proposed scarifying devices are therefore designed to remove significantly greater amounts of ballast than the small amount necessary to widen the channel within the ballast previously occupied by the old tie, thereby permitting insertion of a new railway tie. Additionally, presently available scarifying devices are not particularly suited to mounting on a tie inserting/removal machine.
Accordingly, a scarifying device adapted for mounting on a tie remover/inserter machine is desired. Additionally, a scarifier having laterally reciprocating tines for removing ballast only immediately adjacent to the space occupied by an old railway tie is desired.
The present invention is a railway tie bed scarifier capable of being mounted on a tie remover/inserter machine, and being adapted to remove only that ballast immediately around the space wherein an old tie was formerly located.
The tie bed scarifier includes a plurality of tines, with a preferred number being four, supported by a carriage. The carriage is adapted to be raised into a travel position, and lowered into a work position. In the travel position, the tines are sufficiently raised to clear the railway tracks. In the work position, the tines are positioned slightly below the rails. The tines are mounted on the carriage so that they may reciprocate back and forth within the space to be occupied by a tie, perpendicular to the rails. A preferred configuration of tines includes four tines, with two adapted to travel towards one rail, and the other two adapted to travel towards the other rail. Preferably, the two tines adapted to travel in one direction will be located at opposing sides of the channel within the ballast.
In use, the scarifier will be in its raised travel position until needed. When the scarifier is needed, the tie remover/inserter machine will be moved so that the scarifier is directly over the channel in the ballast wherein an old tie was formerly located. The carriage will be lowered from the travel position to the work position, with the tines kept in their retracted position so that they pass between the tracks. Once the carriage is in the work position, the tines are extended and retracted within the channel left by the removed tie, thereby widening the channel. Once the channel within the ballast has been sufficiently widened, the tines are retracted, the carriage is raised to its travel position, and the tie remover/inserter machine travels sufficiently so that the tie removal/insertion arm is adjacent to the channel.
It is therefore an aspect of the present invention to provide a railway tie bed scarifier capable of being mounted on a tie remover/inserter machine.
It is another aspect of the present invention to provide a tie bed scarifier specifically adapted to widen pre-existing channels left within the ballast by the removal of old ties.
It is a further aspect of the present invention to provide a tie bed scarifier having a simplified design with respect to presently available scarifiers
It is another aspect of the present invention to provide an improved tie insertion method.
These and other aspects of the invention will become apparent through the following description and drawings.